50 results about "DNA Integration" patented technology

Described are recombinant yeast which ferment xylose to ethanol and which maintain their ability to do so when cultured for numerous generations in non-selective media. The preferred yeast contain multiple copies of integrated genes encoding xylose reductase, xylitol dehydrogenase, and xylulokinase fused to promoters which are non-glucose inhibited and which do not require xylose for induction. Also described are preferred methods for integrating multiple copies of exogenous DNA into host cells by transforming cells with replicative / integrative vectors, and then replicating the cells a number of times under selective pressure to promote retention of the vector in subsequent generations. The replicated vectors thus serve to integrate multiple copies of the exogenous DNA into the host cells throughout the replication / selection phase. Thereafter the selective pressure can be removed to promote loss of the vector in subsequent generations, leaving stable integrants of the exogenous DNA.

A method for achieving site specific integration of a desired DNA at a target site in a mammalian cell via homologous recombination is described. This method provides for the reproducible selection of cell lines wherein a desired DNA is integrated at a predetermined transcriptionally active site previously marked with a marker plasmid. The method is particularly suitable for the production of mammalian cell lines which secrete mammalian proteins at high levels, in particular immunoglobulins. Novel vectors and vector combinations for use in the subject cloning method are also provided.

An object of the present invention is to provide an expression vector that allows for stable production of N-deacetylase / N-sulfotransferase 2 in large amounts and a process for production of N-deacetylase / N-sulfotransferase 2 using the same. The present invention provides a recombinant baculovirus expression vector obtained by incorporating into baculovirus DNA, a DNA fragment having lobster L21 DNA, DNA encoding gp67 signal peptide and DNA encoding the 79th to 883rd amino acids of human N-deacetylase / N-sulfotransferase 2 in this order in the 5′ to 3′ direction.

A process for integrating a DNA fragment into the genome of a cell of a monocotyledonous plant, the process comprising the steps of:1) incubating, prior to contacting with the DNA fragment, a culture of untransformed monocotyledonous plant cells on a medium comprising a plant phenolic compound, for a period of time sufficient to stimulate cell division and enhance competence for integration of foreign DNA; and2) contacting the untransformed cells with the DNA fragment under conditions in which the DNA fragment is taken up by the untransformed cells and is stably integrated in the genome of the untransformed cells, to generate transformed cells.

A method of modifying a target region in a host DNA using a donor DNA: wherein the donor DNA having regions homologous to a 5′-side region outside of the target region in the host DNA, a 3′-side region outside of the target region in the host DNA and a first homologous recombination region inside of the target region in the host DNA, respectively, in this order, and further having a first selectable marker gene, an expression-inducing promoter and a second selectable marker gene expressed under the control of the expression-inducing promoter between the region homologous to the 3′-side region and the region homologous to the first homologous recombination region; which method has the steps of: a first step of performing homologous recombination between the donor DNA and the host DNA at the regions of the 5′-side region and the first homologous recombination region, to conduct selection of a host integrated with the donor DNA based on expression of the first selectable marker gene; and a second step of performing homologous recombination, within the host DNA integrated with the donor DNA by the first step, between two regions of the 3′-side region derived from the host DNA and the 3′-side region derived from the donor DNA, to conduct selection of a host whose target region is modified based on expression of the second selectable marker gene under an expression-inducing condition for the expression-inducing promoter; and a selectable marker cassette for use in the method.